A need exists for an circulation sub including a threaded packer sub and a quick coupler body for circulating and dispensing fluid in a well bore that is a efficient, easy to maintain and reliable.
It is known in the art to utilize the pressure of fluid pumped through a work string in a well bore to control a hydraulically activated tool in the well bore.
The hydraulic pressure to operate these tools is typically supplied from the surface of the well bore by pumps. Due to the distances of travel to the location it can be difficult to control the operation of tools in the well bore to provide a constant pressure to give a uniform control.
It has been recognized that being able to control the flow of hydraulic fluid adjacent a hydraulically operated downhole tool would be advantageous. U.S. Pat. No. 5,392,862 describes a drilling mud flow control sub that provides the necessary fluid flow and pressure to activate an expanding remedial tool such as an underreamer, section mill or other cutting tool. The sub consists of a cylindrical sub assembly housing forming a first upstream end and a second downstream end. The housing is threadably connected between a drill string at its first upstream end and a tool at its downstream end. Intermediate the upstream and downstream ends is located a drop ball seat so that insertion of a drop ball will prevent hydraulic fluid flow to the tool. A rupture disc is affixed to a hole formed in the control sub wall normal to the sub axis, above the drop ball seat, so that when obstructed fluid is shunted from the sub.
This flow control sub has reliability problems. A need has exists for a circulating sub that is reliable, easy to use, and easy to maintain.
It is a yet further object of at least one embodiment of the present invention to provide a control sub for use with a hydraulically operated downhole tool which allows selective control of fluid circulation when the tool is run in or tripped from the well.
It is a still further object of the present invention to provide a method of accurately and reliably controlling hydraulic pressure to a hydraulically operated downhole tool in a well bore.
The present embodiments meet these needs.
The present embodiments are detailed below with reference to the listed Figures.